Ethereum Eras
Ethereum's early history is organized into eras defined by major network upgrades. Each era brought new capabilities, fixed vulnerabilities, and shaped the smart contracts deployed during that period.
Frontier
The initial release of Ethereum. A bare-bones implementation for technical users.
2015-07-30 — 2016-03-14
Block 0 – 1,149,999
51 documented contracts
Homestead
The first planned hard fork. Removed the canary contract, adjusted gas costs.
2016-03-14 — 2016-07-20
Block 1,150,000 – 1,919,999
8 documented contracts
DAO Fork
The controversial fork to recover funds from The DAO hack.
2016-07-20 — 2016-10-18
Block 1,920,000 – 2,462,999
9 documented contracts
Tangerine Whistle
Emergency fork to address DoS attacks. Repriced IO-heavy opcodes.
2016-10-18 — 2016-11-22
Block 2,463,000 – 2,674,999
5 documented contracts
Spurious Dragon
Continued DoS protection. State trie clearing.
2016-11-22 — 2017-10-16
Block 2,675,000 – 4,369,999
4 documented contracts